My question is, what if all of a sudden a big crisis occurs like a dollar collapse and millions will buy bitcoin all at once.
Can the current bitcoin infrastructure handle the sudden amount of transactions?
I fear that bitcoin will collapse because people will see that it takes months to do a simple transaction because of the overload.
So to handle the overload we will need to increase block size limit, but will it be healthy/possible to increase block size limit in a few orders of magnitudes, in a short period of time, without ruining the decentralization of bitcoin?
I am afraid that we need our lousy economy to last a few more years until bitcoin is strong enough.
In a global economic crash Bitcoin may become even more important.
Bitcoin can be adapted to support larger amounts of transactions just be increasing the block size. The only reason it's not being increased is politics. It can be increased.
Bitcoin as it is now is not decentralized, that is a myth. Bitcoin is centralized because of chip makers who control the hashing power of the network. Asics centralize Bitcoin and the only way to decentralize it would be to randomize the hashing algorithm so that it's unpredictable and a monopoly cannot form.